How can I reset and align bones?
If you select in edit mode a bone whose "pointing" you want to change, you should be able to go to the tab that looks like a single bone in the Properties panel. Then, under Relations, go to the Parent: drop down menu, clear the current parent, and select the new desired one from the list. Repeat this process until finished.

I used this website when learning to rig. There are many good pointers on it.

Update:

To answer the question in your reply, select the offending foot, and go to the Bone Constraints tab in the Properties panel. Where it says punta_zampa_ant_dx, click and change to punta_zampa_ant_dx.001, the other empty. Repeat for the other offending foot, but select its empty instead of punta_zampa_ant_dx.001.